Validation of the lacrimal specific secretory IgA test for the diagnosis of posterior uveitis presumptively due to Toxoplasma gondii / ValidaÃÃo do teste de IgA secretora especÃfica da lÃgrima em portadores de uveÃte posterior ativa presumivelmente por Toxoplasma gondii

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

Toxoplasmosis is the principal cause of posterior uveitis in Brazil. Serological antibody determination gives some information about the etiological agent of this illness. IgG is considered the natural marker for previous infection while IgM reveals active infection as far as IgA and IgE. Although, as toxoplasmosis is a worldwide distributed parasitosis, IgG may be found in normal subjects and IgM is seldom found elevated in ocular toxoplasmosis. Antibody determination also is done in vitreous humor. Anti T. gondii specific secretory IgA are more frequently found in tears of ocular toxoplasmosis than in IgG positive normal people. This study aimed to validate lacrimal a-T gondii sIgA determination as diagnostic tool for ocular toxoplasmosis. Were analyzed 197 active posterior uveitis patients, 82 of them were clinically diagnosed as golden standard toxoplasmosis uveitis(UPAPTgroup); 74 suffered from other etiologies uveitis (UPAOE group)and 41 not golden standard lesion(UPANO). These consisted in posterior uveitis active lesions adjacent to preexisting scars. Sera specific IgG and IgM determination was done in all the groups through Immunofluorescence. Just one patient had IgM positive and 106(84,8) were positives. ELISA was used for specific lacrimal sIgA determination with crude T. gondii tachizoites as antigens .Sensitivity of 65,9%(IC=60,3-81,5) and specificity of 71,6%(IC=59,8-81,2) was obtained when compared other etiologies and golden standard groups. Positive predictive probability(PPP) was 72% and negative predictive probability (NPP)65,4%. It was collected tears from both eyes, with uveitis and the healthy one, a- T gondii sIgA was also detected in healthy eye tears(p=0,874) It was concluded that this test for sIgA is useful for diagnosis of ocular toxoplasmosis, although some modifications must be done in order to improve sensitivity and specificity

ASSUNTO(S)

iga secretora da lÃgrima uveÃte toxoplasmose medicina toxoplasmosis uveÃtis iga secretory lacrimal

ACESSO AO ARTIGO

Documentos Relacionados